Sinus rhythm (a.k.a. normal sinus rhythm) refers to the normal heart beat originating from the sinoatrial node. This is manifested as an upright P wave in lead II of the ECG. Sinus bradycardia ...

Note the gradual onset of the junctional mechanism as the sinus cycle length increases from 635-670 milliseconds while the ectopic rhythm usurps the sinus rhythm at a more rapid cycle length of ...

The 8 patients studied all had ectopic arrhythmias attributed to digitalis. Pronethalol was given by slow intravenous injection, a total dose of 100 mg. or up to 2.0 mg. per kilogram of body ...